How is carbonate hardness (CH) defined?

Carbonate hardness (CH) is defined as the sum of bicarbonate and carbonate ions present in water. This measurement is crucial in understanding water quality, particularly in relation to the impact on aquatic life and the scaling potential of water systems. The bicarbonate (HCO3-) and carbonate (CO3^2-) ions contribute to the buffering capacity of water, which helps maintain pH and overall water chemistry in natural and engineered systems.

In essence, by summing the concentrations of these two types of ions, one can determine the carbonate hardness, which is an important aspect of total hardness in water. This understanding is fundamental for civil engineers when assessing water quality for construction, treatment, and environmental considerations.